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1 // Copyright 2016 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #ifndef UI_CHROMEOS_TOUCH_ACCESSIBILITY_ENABLER_H_ | |
6 #define UI_CHROMEOS_TOUCH_ACCESSIBILITY_ENABLER_H_ | |
7 | |
8 #include "base/macros.h" | |
9 #include "base/time/tick_clock.h" | |
10 #include "base/timer/timer.h" | |
11 #include "base/values.h" | |
12 #include "ui/chromeos/ui_chromeos_export.h" | |
13 #include "ui/events/event.h" | |
14 #include "ui/events/event_handler.h" | |
15 #include "ui/events/gesture_detection/gesture_detector.h" | |
16 | |
17 namespace aura { | |
18 class Window; | |
19 } | |
20 | |
21 namespace ui { | |
22 | |
23 class Event; | |
24 class EventHandler; | |
25 class TouchEvent; | |
26 | |
27 // A delegate to handle commands in response to detected accessibility gesture | |
28 // events. | |
29 class TouchAccessibilityEnablerDelegate { | |
30 public: | |
31 virtual ~TouchAccessibilityEnablerDelegate() {} | |
32 | |
33 // While the user holds down two fingers on a touch screen, which is the | |
34 // gesture to enable spoken feedback (if held down long enough), play a sound | |
35 // every "tick" (approximately every half-second) to warn the user something | |
36 // is about to happen. | |
37 virtual void PlaySpokenFeedbackToggleCountdown(int tick_count) {} | |
38 | |
39 // Toggles spoken feedback. | |
40 virtual void ToggleSpokenFeedback() {} | |
41 }; | |
42 | |
43 // TouchAccessibilityEnabler triggers turning spoken feedback on or off | |
44 // by holding down two fingers on the touch screen for several seconds. | |
45 class UI_CHROMEOS_EXPORT TouchAccessibilityEnabler : public ui::EventHandler { | |
46 public: | |
47 TouchAccessibilityEnabler(aura::Window* root_window, | |
48 ui::TouchAccessibilityEnablerDelegate* delegate); | |
49 ~TouchAccessibilityEnabler() override; | |
50 | |
51 bool IsInNoFingersDownForTesting() { return state_ == NO_FINGERS_DOWN; } | |
52 bool IsInOneFingerDownForTesting() { return state_ == ONE_FINGER_DOWN; } | |
53 bool IsInTwoFingersDownForTesting() { return state_ == TWO_FINGERS_DOWN; } | |
54 bool IsInWaitForNoFingersForTesting() { | |
55 return state_ == WAIT_FOR_NO_FINGERS; | |
56 } | |
57 void TriggerOnTimerForTesting() { OnTimer(); } | |
58 | |
59 void HandleTouchEvent(const ui::TouchEvent& event); | |
60 | |
61 private: | |
62 // Overridden from ui::EventHandler | |
63 void OnTouchEvent(ui::TouchEvent* event) override; | |
64 | |
65 void StartTimer(); | |
66 void CancelTimer(); | |
67 void OnTimer(); | |
68 | |
69 // Returns the current time of the tick clock. | |
70 base::TimeTicks Now(); | |
71 | |
72 enum State { | |
73 // No fingers are down. | |
74 NO_FINGERS_DOWN, | |
75 | |
76 // One finger is down and it's possible this could be a two-finger-hold. | |
77 ONE_FINGER_DOWN, | |
78 | |
79 // Two fingers are down and stationary and we will trigger enabling | |
80 // spoken feedback after a delay. | |
81 TWO_FINGERS_DOWN, | |
82 | |
83 // This is the "reject" state when we get anything other than two fingers | |
84 // held down and stationary. Stay in this state until all fingers are | |
85 // removed. | |
86 WAIT_FOR_NO_FINGERS | |
87 }; | |
88 | |
89 aura::Window* root_window_; | |
90 | |
91 // Called when we detect a long-press of two fingers. Not owned. | |
92 ui::TouchAccessibilityEnablerDelegate* delegate_; | |
93 | |
94 // The current state. | |
95 State state_; | |
96 | |
97 // The time when we entered the two finger state. | |
98 base::TimeTicks two_finger_start_time_; | |
99 | |
100 // Map of touch ids to their initial locations. | |
101 std::map<int, gfx::PointF> touch_locations_; | |
102 | |
103 // A timer that triggers repeatedly while two fingers are held down. | |
104 base::RepeatingTimer timer_; | |
105 | |
106 // A default gesture detector config, so we can share the same | |
107 // timeout and pixel slop constants. | |
108 ui::GestureDetector::Config gesture_detector_config_; | |
109 | |
110 // When touch_accessibility_enabler gets time relative to real time during | |
111 // testing, this clock is set to the simulated clock and used. | |
112 base::TickClock* tick_clock_; | |
113 | |
114 DISALLOW_COPY_AND_ASSIGN(TouchAccessibilityEnabler); | |
115 }; | |
116 | |
117 } // namespace ui | |
118 | |
119 #endif // UI_CHROMEOS_TOUCH_ACCESSIBILITY_ENABLER_H_ | |
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